Did the FBI guns have a rear barrel sight ???
There are two types of FBI Model 81's...an "early" type and a "late" type. This is one of the oddities of this rifle...it appears to have both the features of the early and late FBI rifles.
The "early" type had the Lyman 41 sight, no rear barrel sight, a high front sight blade and the "Remington" logo and serial number moved over and "stacked" under the Model name ("Woodsmaster")
I have a "civilian", non-FBI Model 81 that displays the usual receiver markings...
You can see the difference. The FBI requested the change because the Lyman 41 sight covered the serial number when the markings were in the usual configuration. You can see that my new Model 81 has the receiver markings of the early FBI model and those markings are unique to the early FBI model.
The "late" type FBI model 81's had regular barrel mounted sights and the receiver markings were in the usual configuration.
The chief distinguishing feature of a late FBI model 81 and a non-FBI model 81 is grooves put in the barrel jacket that were used to induction braze the barrel jacket to the barrel jacket head. This apparently was done by request of the FBI because the barrel jacket head was being shot loose by heavy use. These grooves are unique to FBI model 81's.
If you look closely, you can see that my new Model 81 has these grooves...
I've learned that some of the early FBI model 81's did not have any holes for the rear barrel sight and some did have the rear barrel sight holes, covered by a Lyman sight blank.
It seems to me that there are several possibilities for my rifle...
One, it is an original "early type" FBI model 81 that someone later modified by adding the rear barrel sight, either by removing the rear sight blank and adding a sight, or by having the holes drilled and tapped. However, this would not explain the barrel shroud grooves of the later FBI model 81.
Alternatively...since the Model 81 was a "take down" type rifle and the barrel and fore end could be removed from the receiver, it seems possible that at some point in its life, some one at the FBI accidentally mated the barrel and fore end from a "late" FBI model 81 to the receiver of an early FBI model 81 and it was never corrected.
A third possibility is that at sometime in its FBI service the Bureau returned an early FBI model 81 to Remington to have the brazing done to update it to the later standard.